This disclosure concerns manually operated winches. In particular, the disclosure concerns winches of the type used to secure cargo on transport vehicles such as trucks, trailers, railcars, ships and airplanes.
When heavy or bulky cargo needs to be secured for transport, it is common to use elongate members such as chains, ropes or belts to secure the cargo in place. The elongate members are typically tightened by hand-operated winches. For example, on a trailer designed to transport automobiles, it is typical to secure each automobile by means of a chain that is tightened by a hand-operated winch. Examples of prior winches are described in U.S. Pat. Nos. 3,038,740, 5,145,299, 5,180,262, and 5,314,275.
Prior winches typically include a ratchet mechanism that can hold an elongate member taut. But in cases where cargo has shifted during transit, the elongate member may become slackened, allowing the load to move and cause damage or to shift to a position where it more likely will fall when the elongate member is released at the time of unloading.
Accordingly, there remains a need for winch mechanisms that can be operated easily and will provide a warning if an elongate member becomes unduly slackened.
Features and advantages of new winch systems will be understood by reference to the following detailed description and to the drawings to which it refers.